Since the earliest times, emergency vehicles have depended upon sirens, horns, bells or other types of audible and/or visible warning devices to alert other people in the path of the vehicle. Trains and school buses, also, have depended on such alarms that are generated on or by the vehicle itself. It is here noted that for the purposes of this disclosure, such emergency vehicles, buses, police vehicles, school buses and the like will be referred to as either “warning vehicles” or as “vehicles requiring a right of way,” or, more broadly, as a “warning entity” to encompass not only vehicles, but zones, such as school zones, hospital zones, zones near special needs individuals, and the like, as well, while the vehicle being warned will often be referred to as the “warned vehicle,” or as a “warned entity.” However, the passenger compartments of automobile vehicles have become increasingly insulated from outside noise. Thus, driver and occupants of warned vehicles have become relatively isolated from normally audible danger signals such as sirens, whistles and horns which generate sound waves which are to a large extent attenuated before reaching the driver's ears. This trend towards an increased isolation of the occupants, and especially the driver, has been enhanced because of the use of air conditioning which encourages the driver and passengers to keep the windows of the vehicle closed. When, for example, the windows of a vehicle are closed and the radio is playing, the aforementioned warning signals are often not heard, thereby placing the driver and the passengers in the vehicle in a potentially dangerous circumstance and increasing the probability that a clear right of way may be delayed for the emergency vehicle. Further, a dangerous traffic condition can arise where an unwarned driver obstructs an emergency vehicle which is often traveling at high speed.
Furthermore, whenever an emergency vehicle is traveling under conditions of urgency, the problem of passing through busy street intersections represents a dangerous problem to both the emergency vehicle and to the general traffic at or in the vicinity of the intersection. As discussed above, the problem has become especially severe in recent years when many drivers travel in air conditioned cars with their windows rolled up and often with the radio turned on so that they may be unable to hear the siren of an approaching emergency vehicle. Many serious accidents happen each year as a result of collisions between emergency vehicles and other traffic. In heavy city traffic there is still another problem in relation to the travel of emergency vehicles. As an emergency vehicle approaches a busy intersection and some of the drivers respond to the siren and pull to the curb and halt, as required, busy intersections become filled with vehicles standing still and often completely block the progress of the emergency vehicle.
Accordingly, there is a need for a system that will efficiently warn an occupant of a motor vehicle of not only the approach of another vehicle that should be given the right of way, such as an ambulance, a school bus, or a police vehicle, but will also alert the occupant of the motor vehicle that the motor vehicle is approaching a vehicle that should be given the right of way, such as a school bus that is loading or unloading passengers.
Still further, a constant concern exists as to the safety of vehicles where highways, streets and the like, intersect with railroad crossings. Despite the significant advances in technology utilized in both highway vehicles and trains, accidents involving collisions between trains and highway vehicles continue to occur, which accidents are generally catastrophic in nature. Accordingly, there is a need for a system that will warn an occupant of a motor vehicle of the approach of a train.
The inventor is aware of several attempts to satisfy the just-stated needs. However, these attempts have various shortcomings that inhibit their acceptance. Primary among these shortcomings is the fact that all of the systems of which the inventor is aware, do not make the occupant aware of how close the other vehicle is to his vehicle. Thus, due to this shortcoming, an occupant in a motor vehicle is warned of the proximity of a vehicle requiring a right of way in the same manner whether the other vehicle is very close to the warned vehicle or quite far away. This tends to cause people to ignore a warning because they feel that they are far enough away from the other vehicle to “beat” that warning vehicle and get out of the way in time. This may work in some cases, but if the warning vehicle is quite near, disastrous consequences can result.
Accordingly, there is a need for a system that will warn the occupant of a motor vehicle of the proximity of another vehicle that requires the right of way, and alerts that occupant in a manner that allows him to determine how proximate the warning vehicle is to his own vehicle. Still further, there is a need for such a system that will alert the occupant in a manner that he is not likely to ignore.